Critical Vulnerability in Palo Alto Networks Products
31 May 2026
Palo Alto Networks has identified a critical vulnerability affecting the GlobalProtect portal and gateway of Palo Alto Networks PAN-OS software and Prisma Access that allows attackers to establish unauthorised VPN connections. Users and administrators of affected product versions are advised to update to the latest versions immediately.
Background
Palo Alto Networks has identified a critical vulnerability (CVE-2026-0257) affecting the GlobalProtect portal, gateway of Palo Alto Networks PAN-OS software and Prisma Access. This vulnerability has a Common Vulnerability Scoring System (CVSS v3.1) score of 9.1 out of 10.
Impact
Successful exploitation of this authentication bypass vulnerability could allow a remote unauthenticated attacker to bypass security restrictions and establish an unauthorised VPN connection.
Known Exploitation
This vulnerability is being actively exploited in the wild.
Affected Products
This vulnerability affects the following product versions.
PAN-OS:
PAN-OS 12.1: Versions prior to 12.1.4-h6 and 12.1.7
PAN-OS 11.2: Versions prior to 11.2.4-h17, 11.2.7-h14, 11.2.10-h7 and 11.2.12
PAN-OS 11.1: Versions prior to 11.1.4-h33, 11.1.6-h32, 11.1.7-h6, 11.1.10-h25, 11.1.13-h5 and 11.1.15
PAN-OS 10.2: Versions prior to 10.2.7-h34, 10.2.10-h36, 10.2.13-h21, 10.2.16-h7 and 10.2.18-h6
Prisma Access:
Prisma Access 11.2: Versions prior to 11.2.7-h13
Prisma Access 10.2: Versions prior to 10.2.10-h36
Panorama and Cloud NGFW are not impacted by this vulnerability.
Recommendations
Users and administrators of affected product versions are advised to update to the latest versions immediately. Those running unsupported PAN-OS versions should upgrade to a supported fixed release.
Until patches are applied, administrators are advised to implement one or more of the following mitigation measures:
Use a dedicated certificate for Authentication Override cookies
Disable Authentication Override
References
https://nvd.nist.gov/vuln/detail/cve-2026-0257
https://security.paloaltonetworks.com/CVE-2026-0257
https://thehackernews.com/2026/05/pan-os-globalprotect-authentication.html
